Y42X type vacuum regulator valve, piston instead of a diaphragm pressure regulator valve. Than the diaphragm improve life more than three times. Diameter less than DN50 suggested the use of Y110 and Y116 (screwed) diaphragm-type valve; DN50 caliber greater than or equal suggested the use of Y42X (flanged) piston-type valve. Such valves are adjustable-type valve, the pressure after the valve can be adjusted as needed, and put into use after the valve pressure is always reduced and stabilized at the set value, not because of fluctuations in the valve before pressure, flow change. Valve selection of high quality, reliable performance and long service life.